The present invention relates to a 3D printer printhead, a 3D printer using the same, a method for manufacturing a molded product by using the 3D printer, a method for manufacturing an artificial tooth by using the 3D printer, and a method for manufacturing a machinable glass ceramic molded product by using the 3D printer, the 3D printer printhead comprising: an inlet through which glass wire, which is a raw material, is introduced; a heating means for heating the glass wire introduced through the inlet; a melting furnace for providing a space in which the glass wire is fused; and a nozzle connected to the lower part of the melting furnace so as to temporarily store the fused glass or discharge a targeted amount of the fused glass, wherein the melting furnace includes an exterior frame made from a heat resistant material and an interior frame having a crucible shape, and the interior frame is made from platinum (Pt), a Pt alloy or graphite, which have a low contact angle, or a material having a surface coated with Pt or a diamond-like carbon (DLC) so as to prevent the fused glass from sticking thereto. According to the present invention, the molded product, the artificial tooth, and the machinable glass ceramic molded product can be manufactured with excellent mechanical properties, thermal durability, chemical durability and oxidation resistance and outstanding texture by using the glass wire as a raw material.

The present invention refers to a method for producing a glass body with high silicic-acid content by drawing a softened glass mass from an elongated, substantially cylindrical crucible in that SiO.sub.2 granules are supplied from above into the crucible, the SiO.sub.2 granules are heated to a softening temperature, so that the softened glass mass which comprises a melt surface is formed, the softened glass mass is drawn off via a bottom opening of the crucible so as to form a glass strand, and the glass strand is cut to length to obtain the glass body, wherein due to the supply of the SiO.sub.2 granules a bulk heap is formed that covers the melt surface in part while leaving a melt edge, and wherein the melt surface is optically detected. To improve the fusion behavior of the granules and to suppress or altogether prevent the formation of a sinter crust, it is suggested according to the invention that during the optical detection of the melt surface the width of at least a sub-section of the melt edge is determined consecutively and is set to a value within a target width range through the supply rate of the SiO.sub.2 granules.

A glass rod includes: a glass including a glass composition, wherein the total relative length variation of the semi-major axis tlv.sub.major is determined as an absolute difference between (a) a smallest semi-major axis length I.sub.major(n) and (b) a largest semi-major axis length I.sub.major(n), normalized by the average semi-major axis length l.sub.major(a); wherein the 50 equidistant cross-sections are positioned along the length l.sub.rod of the glass rod, starting at a position of 0.01*l.sub.rod as a first position and employing a plurality of additive increments of 0.02*l.sub.rod for each subsequent position; wherein the relative local area variation lav is determined as an absolute difference between (c) a cross-sectional area that has the largest semi-major axis length I.sub.major(n) and (d) an average value of the cross-sectional areas, normalized by an average value of the cross-sectional areas; wherein the quality index (tlv.sub.major+lav) is 0.090 or less.

One aspect relates to a process for the preparation of a quartz glass body, including providing a silicon dioxide granulate, making a glass melt out of silicon dioxide granulate and making a quartz glass body out of at least part of the glass melt. The silicon dioxide granulate is obtained by providing and processing a silicon dioxide powder. One aspect also relates to silicon dioxide granulate, which is obtained by providing a silicon dioxide powder and processing it. One aspect further relates to a quartz glass body which is obtainable by this process. One aspect further relates to a light guide, an illuminant and a formed body, which are each obtainable by further processing of the quartz glass body.

In illustrative implementations of this invention, a crucible kiln heats glass such that the glass becomes or remains molten. A nozzle extrudes the molten glass while one or more actuators actuate movements of the nozzle, a build platform or both. A computer controls these movements such that the extruded molten glass is selectively deposited to form a 3D glass object. The selective deposition of molten glass occurs inside an annealing kiln. The annealing kiln anneals the glass after it is extruded. In some cases, the actuators actuate the crucible kiln and nozzle to move in horizontal x, y directions and actuate the build platform to move in a z-direction. In some cases, fluid flows through a cavity or tubes adjacent to the nozzle tip, in order to cool the nozzle tip and thereby reduce the amount of glass that sticks to the nozzle tip.

In illustrative implementations of this invention, a crucible kiln heats glass such that the glass becomes or remains molten. A nozzle extrudes the molten glass while one or more actuators actuate movements of the nozzle, a build platform or both. A computer controls these movements such that the extruded molten glass is selectively deposited to form a 3D glass object. The selective deposition of molten glass occurs inside an annealing kiln. The annealing kiln anneals the glass after it is extruded. In some cases, the actuators actuate the crucible kiln and nozzle to move in horizontal x, y directions and actuate the build platform to move in a z-direction. In some cases, fluid flows through a cavity or tubes adjacent to the nozzle tip, in order to cool the nozzle tip and thereby reduce the amount of glass that sticks to the nozzle tip.

In illustrative implementations of this invention, a crucible kiln heats glass such that the glass becomes or remains molten. A nozzle extrudes the molten glass while one or more actuators actuate movements of the nozzle, a build platform or both. A computer controls these movements such that the extruded molten glass is selectively deposited to form a 3D glass object. The selective deposition of molten glass occurs inside an annealing kiln. The annealing kiln anneals the glass after it is extruded. In some cases, the actuators actuate the crucible kiln and nozzle to move in horizontal x, y directions and actuate the build platform to move in a z-direction. In some cases, fluid flows through a cavity or tubes adjacent to the nozzle tip, in order to cool the nozzle tip and thereby reduce the amount of glass that sticks to the nozzle tip.

In illustrative implementations of this invention, a crucible kiln heats glass such that the glass becomes or remains molten. A nozzle extrudes the molten glass while one or more actuators actuate movements of the nozzle, a build platform or both. A computer controls these movements such that the extruded molten glass is selectively deposited to form a 3D glass object. The selective deposition of molten glass occurs inside an annealing kiln. The annealing kiln anneals the glass after it is extruded. In some cases, the actuators actuate the crucible kiln and nozzle to move in horizontal x, y directions and actuate the build platform to move in a z-direction. In some cases, fluid flows through a cavity or tubes adjacent to the nozzle tip, in order to cool the nozzle tip and thereby reduce the amount of glass that sticks to the nozzle tip.